With Florence expected to kick up wind gusts of up to 30 mph this weekend, commercial airlines are asking passengers to monitor flight cancellations and prepare for possible delays.

As of Friday afternoon, no flights had been cancelled at GSP International Airport outside Greer because of the storm, but conditions are expected to worsen overnight.

With that in mind, most airlines are offering fee waivers to GSP passengers who want to change their weekend travel plans.

A spokesman for Delta Airlines said a team of 26 meteorologists monitors the weather, and together with a strategic planning team determines case by case whether flights will continue at various airports. Since Wednesday, Delta has cancelled nearly 200 flights at other airports as a result of Florence.

The priority is to keep flights going, the Delta spokesman said, without compromising safety.

"Anyone flying out the weekend should pay attention," GSP International Airport spokesman Dudley Brown said. "Stay tuned through the airlines."

Joe Lewis, Martha Collins and her two-year-old daughter Piper take a moment to dry off after checking out how Hurricane Florence conditions have affected the beach in North Myrtle Beach on Friday, Sept. 14, 2018. JOSH MORGAN/Staff

Joe Lewis, Martha Collins and her two-year-old daughter Piper take a moment to dry off after checking out how Hurricane Florence conditions have affected the beach in North Myrtle Beach on Friday, Sept. 14, 2018. JOSH MORGAN/Staff

Steve Mann, operational manager for the Cherry Grove Pier, walks in a parking lot near the pier in North Myrtle Beach as wind and rain from Hurricane Florence begins to dramatically increase on Friday, Sept. 14, 2018. JOSH MORGAN/Staff

Steve Mann, operational manager for the Cherry Grove Pier, waits for wind gusts to decrease before crossing North Ocean Boulevard in North Myrtle Beach to check on their pier on Friday, Sept. 14, 2018. JOSH MORGAN/Staff

Storm chaser Emily Pike laughs as she and her friends Brandon Jarvis and Noah Junot play in a wind tunnel at a North Myrtle Beach parking garage on Friday, Sept. 14, 2018. Wind speeds in the area are beginning to increase as Hurricane Florence creeps into coastal South Carolina. JOSH MORGAN/Staff

Storm chasers Brandon Jarvis, left, and Emily Pike try to suspend themselves in the air in a wind tunnel at a parking garage in North Myrtle Beach as wind speeds begin to increase due to Hurricane Florence on Friday, Sept. 14, 2018. JOSH MORGAN/Staff

Storm chasers Emily Pike, left, and Brandon Jarvis try to suspend themselves in the air in a wind tunnel at a parking garage in North Myrtle Beach as wind speeds begin to increase due to Hurricane Florence on Friday, Sept. 14, 2018. JOSH MORGAN/Staff

A North Myrtle Beach Public Safety officer drives down North Ocean Boulevard as the first rain from an outer band of Hurricane Florence hits the Cherry Grove Pier area of North Myrtle Beach on Thursday, Sept. 13, 2018. JOSH MORGAN/Staff

Haleigh Washington, 13, plays catch at Cherry Grove Beach in North Myrtle Beach as the first rain from a stray outer band of Hurricane Florence hits the area on Thursday, Sept. 13, 2018. JOSH MORGAN/Staff

A North Myrtle Beach public safety officer walks back to his vehicle after informing beachgoers of a 7 p.m. curfew due to the arrival of Hurricane Florence on Thursday, Sept. 13, 2018. JOSH MORGAN/Staff

Beachgoers take advantage of their last opportunity to enjoy the ocean at North Myrtle Beach on Thursday, Sept. 13, 2018 before Hurricane Florence is expected to arrive later this evening into tomorrow. JOSH MORGAN/Staff

Karen Glass, left, and Deborah Murray leave Cherry Grove Beach in North Myrtle Beach after being informed of a curfew due to the arrival of Hurricane Florence on Thursday, Sept. 13, 2018. JOSH MORGAN/Staff

A North Myrtle Beach Public Safety officer drives down North Ocean Boulevard as the first rain from an outer band of Hurricane Florence hits the Cherry Grove Pier area of North Myrtle Beach on Thursday, Sept. 13, 2018. JOSH MORGAN/Staff

Noah Peele, 20, and Haleigh Washington, 13, play catch at Cherry Grove Beach in North Myrtle Beach as the first rain from a stray outer band of Hurricane Florence hits the area on Thursday, Sept. 13, 2018. JOSH MORGAN/Staff

Wind gusts up to 30 mph

Collins said that he noticed conditions changing quickly during the day Friday. Pilots share information they observe through a system called "PIREP" (pilot reports), he said, and he called in a report on the wind as he landed Friday morning.

"I flew with a student at 10 a.m. today and it was smooth leaving," Collins said. "One hour later, we experienced moderate turbulence coming back to land. That indicated to me that conditions were getting worse, as I had expected."

At 3,000 feet this morning, wind reached about 35 mph, and Collins said he could see it pushing his aircraft to the side.

The National Weather Service forecast wind gusts on the ground of up to 23 mph by Friday afternoon, increasing to 30 mph by 11 a.m. Saturday and continuing until about 11 p.m. Wind gusts will be back down to 23 mph by 2 a.m. Sunday.

The larger concern among Upstate meteorologists and emergency managers has been flash floods and related landslides in steeper areas. Hurricane-related rainfall is predicted to commence at 8 a.m. Saturday, with up to a foot of rain expected in some areas over the weekend.

Airport will stay open

GSP airport will likely remain open throughout the storm, Brown said, as it takes wind gusts in excess of 75 mph to close the air-traffic control tower there.

"If we don't have someone up there, we have to consider closing the airport," Brown said.

He said the airport has never closed in the last five years and that people waiting for flights to resume in the event of cancellations are welcome to stick around. The airport has a generator and a backup generator to keep the lights on.

"Our goal is to stay up and operational," Brown said. "We will be here."

During Hurricane Irma last year hundreds of flights were delayed or canceled at Hartsfield-Jackson Airport in Atlanta. People napped as they waited out the storm.(Photo: Ken Ruinard/Independent Mail)

How to rebook

Airlines are granting a range of fee waivers for passengers delayed by the weather, but details vary.

► Allegiant: Flights could be disrupted through Sunday, and passengers can ask for a one-time change to travel plans without incurring a fee. Call Allegiant Customer Care at 702-505-8888.

► American Airlines: If you bought your ticket before Monday and are scheduled to fly between now and Monday, Sept. 17, the airline will let you delay flying for a few days without a flight-change fee. Go to the airline's "Find your trip" site for more details.

► Delta: Passengers affected by the weather may change flights without incurring a fee; the airline has also waived baggage and pet fees. Check delta.com for details.

► Frontier: Customers traveling between now and Sunday, Sept. 16, to, from or through GSP and who bought their tickets before Monday can make a travel change without a fee. Travel must be completed no later than Oct. 1. Customers with cancelled flights can also ask for a refund. Call 801-401-9000.

► Southwest: For flights between now and Monday, Sept. 17, GSP customers can rebook or travel standby (within 14 days) without paying a fee. GSP customers may also change their origin or destination to Atlanta if they want to. Call 1-800-435-9792.

► United: United is offering a travel waiver for customers ticketed on flights to, from or through GSP through Sunday. Customers may reschedule through Sept. 20 without a fee. The airline is also waiving pet and baggage fees. Call 1-800-UNITED-1 to rebook.